Re: [DNSOP] back to: Some distinctions and a request

[Robert Edmonds <[e-mail]>]

manning wrote:
> Hum…   “domain-looking-string” …  Per RFC 1945, we read:
> "3.2.2 http URL
> 
> 
>    The "http" scheme is used to locate network resources via the HTTP
>    protocol. This section defines the scheme-specific syntax and
>    semantics for http URLs.
> 
>        http_URL       = "http:" "//" host [ ":" port ] [ abs_path ]
> 
>        host           = <A legal Internet host domain name
>                          or IP address (in dotted-decimal form),
>                          as defined by 
> Section 2.1 of RFC 1123
> >
> 
>        port           = *DIGIT”
> 
> So then the question on the table is,  What is a “legal host domain name”?   RFC 1123, using SMTP as the example, says:
> 
> "5.3.5  Domain Name Support
> 
>          SMTP implementations MUST use the mechanism defined in 
>          Section 6.1 for mapping between domain names and IP addresses.  This
>          means that every Internet SMTP MUST include support for the
>          Internet DNS.”
> 
> This STRONGLY suggests that “domain-looking-string” is , in fact,  a host that is identified using the Internet DNS.

Have a look at the later HTTP/1.1 RFCs (7230) and the URI generic syntax
RFC (3986).  RFC 7230 defines http URIs, but it relies on the URI
generic syntax (RFC 3986) to define "uri-host"'s, and that specification
explicitly declines to require that "domain-looking-strings" be Internet
DNS names:

3.2.2.  Host

   [...]

   This specification does not mandate a particular registered name
   lookup technology and therefore does not restrict the syntax of reg-
   name beyond what is necessary for interoperability.  Instead, it
   delegates the issue of registered name syntax conformance to the
   operating system of each application performing URI resolution, and
   that operating system decides what it will allow for the purpose of
   host identification.  A URI resolution implementation might use DNS,
   host tables, yellow pages, NetInfo, WINS, or any other system for
   lookup of registered names.  However, a globally scoped naming
   system, such as DNS fully qualified domain names, is necessary for
   URIs intended to have global scope.  URI producers should use names
   that conform to the DNS syntax, even when use of DNS is not
   immediately apparent, and should limit these names to no more than
   255 characters in length.

   [...]

-- 
Robert Edmonds